Spark plug



J. J. NORRIS.

SPARK PLUG.

APPLICATION FILED MAR. 6, [920.

wzyz.

Patented Jan. 10, 1922.

JOHN J. NORRIS, OF SUTTONS BAY, MICHIGAN.

SPARK PLUG.

Specification of Letters Patent.

Patented Jan. 10, 1922.

Application filed March 6, 1920. Serial No. 363,636.

To all whom it may concern:

Be it known that 1, JOHN J. NORRIS, a citizen of the United States,residing at Suttons Bay, in the county of Leelanau and State ofMichigan, have invented certainnew and useful Improvements in a SparkPlug, of which the following is a specification.

The invention relates to a spark plug and more particularly to theconstruction of electrodes for spark plugs.

The primary object of the invention is the provision of a spark plug,wherein the electrodes thereof have formed thereon novel sparking tipsso as to increase the efliciency of the spark plug, as the accumulationof carbon and oil at the tips is eliminated and at the same time therequisite sparking may be effected.

Another object of the invention is the provision of a spark plug of thischaracter, wherein the sparking tips of the electrodes can be moreeasily cleaned and a wider sparking surface is provided to assure a morepositive and greater sparking action of the plug in the use thereof.

A further object of the invention is the provision of a spark plug ofthis character, wherein the electrodes thereof are provided withenlarged terminals spaced opposite each other in alignment with thecentral axis of the plug and are formed with opposed registering flatsurfaces, spaced the required distance apart for effecting the sparkinggap, the formation of the terminals of the electrodes being such as toprevent the accumulation of carbon upon the flat surfaces as the latterwill be shielded by the enlarged terminals and the carbon deflectedtherefrom.

A still further object of the invention is the provision of a spark plugof this character, which is extremely simple in construction, thoroughlyreliable and efiicient in its purpose, strong, durable andinexpensive'to manufacture.

With these and other objects in view, the invention consists in thefeatures of construction, combination and arrangement of parts, as'willbe hereinafter fully described, illustrated in the accompanying drawingsand pointed out in the claim hereunto appended.

In the accompanying drawings:

Figure 1 is a side elevation of the spark plug constructed in accordancewith the invention, a portion of the shell thereof being broken away toshow in detail the terminals of the electrodes.

Figure 2 is a bottom plan view of the spark. plug.

' Similar reference characters indicate corresponding parts throughoutthe several views of the drawings.

' Referring to the drawings in detail the spark plug comprises an outershell 5, which is of the usual well known construction having the theexternally threaded lower portion 6 for the attachment thereof in thecylinder of an internal combustion engine and fitted within this shellis the porcelain or other like insulator core 7 the same being retainedin the shell 5 through the medium of a lock nut 8 removably fitted inthe upper end of said shell in the ordinary well known manner, the upperend portion of the shell being externally shaped to provide wrenchengaging surfaces 9 as usual for the convenient mounting of the shell 5within the cylinder of the internal combustion engine.

Fitted centrally within the core 7 is the primary or main electrode 10which extends beyond the upper end of the core 7 and has threadedthereon as usual a binding nut 11 for the fastening of one of thecurrent wires of an electric ignition system therewith, the lowerportion of the electrode 10 being extended beyond the lower end of thecore 7 and terminates approximately flush with the lower edge of theshell 5 or in other words in the same plane with said edge.

Fitted within the lower edge of the shell 5 is the secondary orauxiliary electrode 12, the end thereof being engaged in the shell isfastened rigid in any suitable manner, while the opposite end portion ofsaid electrode 12 is curved inwardly and upwardly to have its extremityvertically aligned with the electrode 10 as is clearly shown in Figure 1of the drawings.

The\electrodes l0 and 12 are formed with enlarged circular shapedsparking ends 13 provided with opposed flat faces 14: which are spacedthe required distance apart to provide the requisite sparking gapbetween the faces 14, the enlarged ends 13 being shaped so that when thesame are in registration with each other the fiat surfaces 14 will beshielded by said ends 13 to prevent the accumulation of carbon or oilupon the surfaces 14 and at the same time will increase the sparkingcapacity of the electrodes l0 and- 12 to assure maximum sparkingeffectin the use of the spark plug.

It will be apparent from Fi ure 1 of the drawings that the enlarged en s13 in their disposition with respect to each other are of reversedapproximately cone shape so as to shield the flat surfaces 14 to shedcarbon and foreign matter from said surfaces and thus avoiding thepossibility of the retarding of the'spark created at the sparking tipsof the electrodes of the spark plug and maximum sparking surface isprovided at the tips of said electrodes as Will be clearly apparent.

From the foregoing it is thought that the hereto.

JOHN J. NORRIS.

